基数排序

 1 #include <stdio.h>

 2 #include <string.h>

 3 const int N = 10000;

 4 const int RADIX = 10;

 5 int a[N];

 6 int count[RADIX];

 7 void radixSort(int n)

 8 {

 9     int *bucket = new int[RADIX];

10     int d = 1;

11     int i;

12     for(int k=1; k<=10; k++)//最大数为1<<32 - 1,为10位数

13     {

14         for(i=0; i<RADIX; ++i)

15             count[i] = 0;

16         for(i=0; i<n; ++i)

17             count[a[i]/d%10] ++;

18         for(i=1; i<RADIX; ++i)

19             count[i] += count[i-1];

20         for(i=RADIX-1; i>=0; --i)

21         {

22             int j = a[i]/d%10;

23             bucket[count[j]-1] = a[i];

24             count[j]--;

25         }

26         for(i=0; i<n; ++i)

27             a[i] = bucket[i];

28         d *= 10;

29     }

30 }

31 int main()

32 {

33     int n,i;

34     scanf("%d",&n);

35     for(i=0; i<n; ++i)

36         scanf("%d",&a[i]);

37     radixSort(n);

38     for(i=0; i<n; ++i)

39         printf("%d ",a[i]);

40     return 0;

41 }